The main tendencies in plant space and gravitational biology today in countries, which are members of the International Space Life Sciences Working Group, are considered. Certain examples of available and workable technical facilities for space and groundbased experiments with plants are presented. An urgent idea on the utilization of plants as the necessary components of bioregenerative life-support systems in interplanetary space flights is emphasized to be very far from its practical realization that requires space green-houses of the sufficient volume, as well as development and testing of technologies for a green conveyer onboard space vehicles and performing the genetic and breeding works to obtain the varieties of crops adapted to spaceflight conditions.